US20040089148A1 - Method and device at a piston-cylinder device - Google Patents
Method and device at a piston-cylinder device Download PDFInfo
- Publication number
- US20040089148A1 US20040089148A1 US10/250,808 US25080803A US2004089148A1 US 20040089148 A1 US20040089148 A1 US 20040089148A1 US 25080803 A US25080803 A US 25080803A US 2004089148 A1 US2004089148 A1 US 2004089148A1
- Authority
- US
- United States
- Prior art keywords
- casing
- piston
- tubular casing
- arrangement
- seal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/02—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using gas only or vacuum
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F7/00—Vibration-dampers; Shock-absorbers
- F16F7/12—Vibration-dampers; Shock-absorbers using plastic deformation of members
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/32—Details
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/32—Details
- F16F9/3207—Constructional features
- F16F9/3235—Constructional features of cylinders
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F2230/00—Purpose; Design features
- F16F2230/24—Detecting or preventing malfunction, e.g. fail safe
Definitions
- the present invention relates to a method and an arrangement in a piston-cylinder arrangement, more specifically a method and an arrangement which in the event of a malfunction or deformation of the said piston-cylinder arrangement permits controlled discharge of the pressure therein.
- U.S. Pat. No. 3,995,842 A discloses a pneumatic spring of piston-cylinder type.
- This spring is of the type used in order to relieve the pressure on the bonnet or boot of a motor vehicle and has been provided with breakable sections in the cylinder wall and on the piston rod in the form of a reduced cross-section. These sections give way under increased pressure caused by fire or collision, thereby releasing compressed gas from the cylinder into the surrounding air through an opening in the cylinder wall or the piston rod under conditions that cannot eject the pieces of the cylinder at high speed.
- the object of the invention is to provide a method and an arrangement in a piston-cylinder arrangement which can more safely cope with damage to a tubular casing due to overload, flash-over and/or fatigue and permit a controlled discharge of the pressure in the arrangement.
- gas-filled springs are therefore used to support the sheet metal holder and they are subjected to pressure at the beginning of the pressing process, to be relieved of pressure again on the completion of sheet metal forming when the press slide and the press upper part move upwards.
- the gas-filled springs are subjected to loading is determined by the pressing process, by the appearance of the pressed sheet metal part and by the stroke length used.
- FIG. 1 is a section through a gas-filled spring arrangement in a position with piston projecting, with markings for weakened areas in the tubular casing of the gas-filled spring arrangement,
- FIGS. 2A and 2B are a corresponding section through the gas-filled spring arrangement according to FIG. 1 in an “overloaded” position with the tubular casing deformed
- FIGS. 3A and 3B are sections through a gas-filled spring with markings for weakened areas on the outside and/or inside of the tubular casing of the gas-filled spring in a normal working position, and in an overload position respectively, and
- FIGS. 4A and 4B are sections through a gas accumulator with markings for weakened areas on the outside and/or inside of the tubular casing of the gas accumulator in a normal working position, and in an overload position permitting discharge of the excess pressure in the gas accumulator.
- FIG. 1 shows the gas-filled spring arrangement A retracted in a recess, for example a base, the arrangement comprising a cylindrical sleeve or tubular casing 1 , a piston/piston rod part 2 , a guide/end 3 and a filling connection B in the tubular casing 1 .
- the arrangement A may also be “non-retracted” in relation to a machine or machine part. Sealing arrangements 4 , 5 and 6 between tubular casing 1 and piston/piston rod part 2 and guide/end 3 ensure a normally leak-free use of the arrangement A.
- FIG. 1A shows the piston/piston rod part 2 in an projecting position with fracture or deformation marks or grooves 7 A, 7 B in the tubular casing of the arrangement.
- These marks or grooves may be placed on the inside and/or outside of the tubular casing 1 and result in a weakening of the wall of the tubular casing, which means that in the event of a permitted stress being exceeded the material in the wall can give way and move outwards, thereby negating the action of the seal through the gap 8 that occurs and thus permitting discharge of the excess pressure inside the chamber of the tubular casing 1 .
- the location, appearance and degree of such bulging can be predetermined by selecting the location and size of the grooves and/or the marks.
- the weakening of the tubular casing and the choice of material therein can be made in such way that a fracture or cracking occurs in the tubular casing.
- material and weakening are selected in such a way that the deformation of the tubular casing does not result in the material fracturing, but to the occurrence of bulging in direct proximity to the said sealing arrangement 4 between piston/piston rod part 2 , guide/end 3 and tubular casing 1 , the reduced contact pressure between seal and tubular casing permitting a controlled discharge of the gas to occur past the seal 4 .
- the weakening of the tubular casing that occurred is situated in close proximity to the lower end of a guide/seal 4 . This is done in order to ensure that the bulging of the tubular casing occurs on the intended side of the guide/seal 4 .
- a small axial groove can be provided in the guide, into which groove the gas can escape. This is done in order to ensure that any spraining of the tubular casing against the piston/piston rod, guide/end, that is to say metal against metal, will not block the desired discharge.
- FIG. 2A shows a corresponding section through the gas-filled spring arrangement according to FIG. 1 in an “overloaded” position with the tubular casing 1 deformed, the discharge of the gas being shown by the arrows a.
- FIG. 2B shows an enlargement of the gap 8 that is formed between the wall of the tubular casing and the seal 4 .
- FIG. 3A shows a section through a gas-filled spring with markings for weakened areas on the outside and/or inside of the tubular casing 1 of the gas-filled spring.
- the spraining sustained by the casing wall can permit discharge of the excess pressure in the gas-filled spring in one or two directions.
- FIG. 3B like FIG. 2A, shows how the discharge of the gas can occur past the deformed wall of the tubular casing 1 and past the seal 9 .
- the deformation of the casing 1 also permits discharge past the seal 4 ′, that is to say in two directions simultaneously.
- FIGS. 4A and 4B show the invention applied in a gas accumulator A′′ with end 3 ′ and seal 10 against the casing 1 ′′.
- a weakening mark 7 ′′A, 7 ′′B in the tubular casing 1 ′′ of the gas accumulator A′′ gives rise to the formation of a bulge or gap 8 ′′ in the event of a stress occurring that deforms the tubular casing 1 ′′.
- the arrows a′′ represent the desired and controlled discharge of the excess pressure in the gas accumulator.A′′.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Fluid-Damping Devices (AREA)
- Pistons, Piston Rings, And Cylinders (AREA)
- Actuator (AREA)
- Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
Description
- The present invention relates to a method and an arrangement in a piston-cylinder arrangement, more specifically a method and an arrangement which in the event of a malfunction or deformation of the said piston-cylinder arrangement permits controlled discharge of the pressure therein.
- As an example of the prior art, reference will be made to U.S. Pat. No. 3,995,842 A, which discloses a pneumatic spring of piston-cylinder type. This spring is of the type used in order to relieve the pressure on the bonnet or boot of a motor vehicle and has been provided with breakable sections in the cylinder wall and on the piston rod in the form of a reduced cross-section. These sections give way under increased pressure caused by fire or collision, thereby releasing compressed gas from the cylinder into the surrounding air through an opening in the cylinder wall or the piston rod under conditions that cannot eject the pieces of the cylinder at high speed.
- The object of the invention is to provide a method and an arrangement in a piston-cylinder arrangement which can more safely cope with damage to a tubular casing due to overload, flash-over and/or fatigue and permit a controlled discharge of the pressure in the arrangement.
- The stated object of the invention is achieved in that the arrangement has the characteristics specified in the patent claims.
- The invention will be described in connection with gas accumulators and with use of gas-filled springs in a sheet metal press, in which the function of the gas-filled springs is, among other things, to hold the sheet metal during the forming processing and to separate the tool halves when sheet metal forming has been carried out. Gas-filled springs are therefore used to support the sheet metal holder and they are subjected to pressure at the beginning of the pressing process, to be relieved of pressure again on the completion of sheet metal forming when the press slide and the press upper part move upwards. To what extent the gas-filled springs are subjected to loading is determined by the pressing process, by the appearance of the pressed sheet metal part and by the stroke length used. Even if the characteristic of the gas-filled springs is selected according to the appearance and shape of the pressed sheet metal part, with the aim of achieving full control of the press cycle, there is a risk that the press cycle cannot always be safely controlled. The gas-filled springs are damaged by covering an excessively long stroke, that is to say a stroke that exceeds their defined nominal stroke length. Such overloading risks permanently damaging the piston/piston rod/guide and tubular casing of the gas-filled spring. Depending on the degree of overload there is always a risk in the longer term of a reduced service life of the gas-filled spring. There is also an obvious risk of the tubular casing of the gas-filled spring being damaged in such a way that an uncontrollable leakage occurs. Repeated stressing can also give rise to a fatigue fracture in the cylindrical or casing part of the gas-filled spring.
- The invention will now be described in more detail with reference to examples of embodiments shown in the drawings attached, in which:
-
- FIGS. 2A and 2B are a corresponding section through the gas-filled spring arrangement according to FIG. 1 in an “overloaded” position with the tubular casing deformed,
- FIGS. 3A and 3B are sections through a gas-filled spring with markings for weakened areas on the outside and/or inside of the tubular casing of the gas-filled spring in a normal working position, and in an overload position respectively, and
- FIGS. 4A and 4B are sections through a gas accumulator with markings for weakened areas on the outside and/or inside of the tubular casing of the gas accumulator in a normal working position, and in an overload position permitting discharge of the excess pressure in the gas accumulator.
- FIG. 1 shows the gas-filled spring arrangement A retracted in a recess, for example a base, the arrangement comprising a cylindrical sleeve or
tubular casing 1, a piston/piston rod part 2, a guide/end 3 and a filling connection B in thetubular casing 1. It must be pointed out in this context that the arrangement A may also be “non-retracted” in relation to a machine or machine part.Sealing arrangements tubular casing 1 and piston/piston rod part 2 and guide/end 3 ensure a normally leak-free use of the arrangement A. FIG. 1A shows the piston/piston rod part 2 in an projecting position with fracture or deformation marks orgrooves tubular casing 1 and result in a weakening of the wall of the tubular casing, which means that in the event of a permitted stress being exceeded the material in the wall can give way and move outwards, thereby negating the action of the seal through thegap 8 that occurs and thus permitting discharge of the excess pressure inside the chamber of thetubular casing 1. The location, appearance and degree of such bulging can be predetermined by selecting the location and size of the grooves and/or the marks. Thus the weakening of the tubular casing and the choice of material therein can be made in such way that a fracture or cracking occurs in the tubular casing. According to a preferred embodiment of the invention material and weakening are selected in such a way that the deformation of the tubular casing does not result in the material fracturing, but to the occurrence of bulging in direct proximity to the saidsealing arrangement 4 between piston/piston rod part 2, guide/end 3 andtubular casing 1, the reduced contact pressure between seal and tubular casing permitting a controlled discharge of the gas to occur past theseal 4. The weakening of the tubular casing that occurred is situated in close proximity to the lower end of a guide/seal 4. This is done in order to ensure that the bulging of the tubular casing occurs on the intended side of the guide/seal 4. - In order to further ensure discharge of the gas, a small axial groove can be provided in the guide, into which groove the gas can escape. This is done in order to ensure that any spraining of the tubular casing against the piston/piston rod, guide/end, that is to say metal against metal, will not block the desired discharge.
- FIG. 2A shows a corresponding section through the gas-filled spring arrangement according to FIG. 1 in an “overloaded” position with the
tubular casing 1 deformed, the discharge of the gas being shown by the arrows a. When the load has been removed, therefore, there will be no significant excess pressure in the chamber, for which reason any force that may act outwards on thepiston 2 will be very slight. FIG. 2B shows an enlargement of thegap 8 that is formed between the wall of the tubular casing and theseal 4. - FIG. 3A shows a section through a gas-filled spring with markings for weakened areas on the outside and/or inside of the
tubular casing 1 of the gas-filled spring. With this embodiment the spraining sustained by the casing wall can permit discharge of the excess pressure in the gas-filled spring in one or two directions. FIG. 3B, like FIG. 2A, shows how the discharge of the gas can occur past the deformed wall of thetubular casing 1 and past theseal 9. The deformation of thecasing 1 also permits discharge past theseal 4′, that is to say in two directions simultaneously. - FIGS. 4A and 4B show the invention applied in a gas accumulator A″ with
end 3′ and seal 10 against thecasing 1″. A weakening mark 7″A, 7″B in thetubular casing 1″ of the gas accumulator A″ gives rise to the formation of a bulge orgap 8″ in the event of a stress occurring that deforms thetubular casing 1″. The arrows a″ represent the desired and controlled discharge of the excess pressure in the gas accumulator.A″. - The invention is not limited to the examples of embodiments described above but lends itself to modifications within the scope of the patent claims specified below.
Claims (7)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE0103756A SE520224C2 (en) | 2001-11-12 | 2001-11-12 | Method and apparatus of a piston-cylinder device comprising a breaking or breaking instruction |
PCT/SE2002/002002 WO2003054415A1 (en) | 2001-11-12 | 2002-11-05 | Method and device at a piston-cylinder device |
Publications (2)
Publication Number | Publication Date |
---|---|
US20040089148A1 true US20040089148A1 (en) | 2004-05-13 |
US6971303B2 US6971303B2 (en) | 2005-12-06 |
Family
ID=20285947
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/250,808 Expired - Lifetime US6971303B2 (en) | 2001-11-12 | 2002-11-05 | Method and device at a piston-cylinder device |
Country Status (8)
Country | Link |
---|---|
US (1) | US6971303B2 (en) |
EP (1) | EP1366308B1 (en) |
KR (1) | KR100886195B1 (en) |
AU (1) | AU2002349628A1 (en) |
DE (2) | DE60205087T2 (en) |
ES (1) | ES2244819T3 (en) |
SE (1) | SE520224C2 (en) |
WO (1) | WO2003054415A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11226022B2 (en) | 2016-06-22 | 2022-01-18 | Stromsholmen Ab | Piston cylinder device with protection arrangement and method of protecting a piston cylinder device against overload or failure of the piston cylinder device |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102006008901A1 (en) * | 2006-02-27 | 2007-08-30 | GM Global Technology Operations, Inc., Detroit | Pneumatic actuator for active hood, has piston which is guided on cylinder between neutral position and deployed position, where piston is pre-stressed in neutral position by spring element towards extended position |
TR200807829A2 (en) | 2008-10-17 | 2009-07-21 | Destek Otomoti̇v Yan Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇ | A safety device for gas springs |
KR101240446B1 (en) * | 2011-04-14 | 2013-03-11 | 이병철 | Buffer |
ES2405937B1 (en) * | 2011-11-29 | 2014-07-30 | Técnicas Aplicadas De Presión, S.L. | GAS CYLINDER-PISTON DESIGN |
ES2405850B1 (en) * | 2011-11-29 | 2014-07-30 | Técnicas Aplicadas De Presión, S.L. | GAS CYLINDER-PISTON DESIGN |
US9551394B2 (en) | 2013-03-15 | 2017-01-24 | Dadco, Inc. | Overtravel pressure relief for a gas spring |
US9347510B2 (en) * | 2013-03-15 | 2016-05-24 | Dadco, Inc. | Overtravel pressure relief for a gas spring |
EP2933524A1 (en) | 2014-04-15 | 2015-10-21 | Destek Otomotiv Yan Sanayi ve Ticaret Anonim Sirketi | A safety configuration for nitrogen gas springs |
SE1450765A1 (en) | 2014-06-19 | 2015-12-20 | Strömsholmen Ab | Gas spring and safety procedure for gas spring |
JP6595242B2 (en) * | 2014-07-31 | 2019-10-23 | スペシャル・スプリングス・ソシエタ・ア・レスポンサビリタ・リミタータ | Gas operated spring |
ITUB20159608A1 (en) * | 2015-12-21 | 2017-06-21 | Special Springs Srl | GAS SPRING WITH EXTRA-RUN SAFETY DEVICE |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3995842A (en) * | 1974-12-07 | 1976-12-07 | Stabilus Gmbh | Pneumatic spring with safety release |
US5064030A (en) * | 1989-06-19 | 1991-11-12 | Fichtel & Sachs Ag | Impact damping unit |
US5620067A (en) * | 1994-07-28 | 1997-04-15 | Suspa Compart Aktiengesellschaft | Longitudinally adjustable gas spring with dual layered cylinder |
US6322059B1 (en) * | 1998-07-23 | 2001-11-27 | Barnes Group Inc. | Low contact force spring |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA2028573A1 (en) * | 1989-11-08 | 1991-05-09 | Bernard Joseph Wallis | Gas spring |
US5735371A (en) * | 1991-01-21 | 1998-04-07 | Stabilus Gmbh | Cylinder piston device |
-
2001
- 2001-11-12 SE SE0103756A patent/SE520224C2/en not_active IP Right Cessation
-
2002
- 2002-11-05 AU AU2002349628A patent/AU2002349628A1/en not_active Abandoned
- 2002-11-05 EP EP02783911A patent/EP1366308B1/en not_active Expired - Lifetime
- 2002-11-05 KR KR1020037008985A patent/KR100886195B1/en active IP Right Grant
- 2002-11-05 ES ES02783911T patent/ES2244819T3/en not_active Expired - Lifetime
- 2002-11-05 DE DE60205087T patent/DE60205087T2/en not_active Expired - Lifetime
- 2002-11-05 DE DE0001366308T patent/DE02783911T1/en active Pending
- 2002-11-05 US US10/250,808 patent/US6971303B2/en not_active Expired - Lifetime
- 2002-11-05 WO PCT/SE2002/002002 patent/WO2003054415A1/en not_active Application Discontinuation
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3995842A (en) * | 1974-12-07 | 1976-12-07 | Stabilus Gmbh | Pneumatic spring with safety release |
US5064030A (en) * | 1989-06-19 | 1991-11-12 | Fichtel & Sachs Ag | Impact damping unit |
US5620067A (en) * | 1994-07-28 | 1997-04-15 | Suspa Compart Aktiengesellschaft | Longitudinally adjustable gas spring with dual layered cylinder |
US6322059B1 (en) * | 1998-07-23 | 2001-11-27 | Barnes Group Inc. | Low contact force spring |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11226022B2 (en) | 2016-06-22 | 2022-01-18 | Stromsholmen Ab | Piston cylinder device with protection arrangement and method of protecting a piston cylinder device against overload or failure of the piston cylinder device |
US11761504B2 (en) | 2016-06-22 | 2023-09-19 | Stromsholmen Ab | Piston cylinder device with protection arrangement and method of protecting a piston cylinder device against overload or failure of the piston cylinder device |
Also Published As
Publication number | Publication date |
---|---|
KR20040073276A (en) | 2004-08-19 |
ES2244819T3 (en) | 2005-12-16 |
EP1366308A1 (en) | 2003-12-03 |
US6971303B2 (en) | 2005-12-06 |
SE0103756D0 (en) | 2001-11-12 |
EP1366308B1 (en) | 2005-07-20 |
SE0103756L (en) | 2003-05-13 |
WO2003054415A1 (en) | 2003-07-03 |
DE60205087D1 (en) | 2005-08-25 |
DE02783911T1 (en) | 2004-07-15 |
AU2002349628A1 (en) | 2003-07-09 |
KR100886195B1 (en) | 2009-02-27 |
DE60205087T2 (en) | 2006-06-08 |
SE520224C2 (en) | 2003-06-10 |
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Legal Events
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AS | Assignment |
Owner name: STROMSHOLMEN AB, SWEDEN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:JOHANSSON, MARTEN;NORDVALL, PER;GUSTAFFSON, KRISTER;REEL/FRAME:014835/0784 Effective date: 20030814 |
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AS | Assignment |
Owner name: STROMSHOLMEN AB, SWEDEN Free format text: RE-RECORDED TO CORRECT THIRD ASSIGNOR'S NAME ON AN ASSIGNMENT DOCUMENT PREVIOUSLY RECORDED AT REEL 014835 FRAME 0784.;ASSIGNORS:JOHANSSON, MARTEN;NORDVALL, PER;GUSTAFSSON, KRISTER;REEL/FRAME:015078/0913 Effective date: 20030814 |
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Free format text: PATENTED CASE |
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